Does dopamine availability influence the effect of brain stimulation on mind-wandering?
based on reviews by Chris Chambers and 1 anonymous reviewer
On the neural substrates of mind wandering and dynamic thought: A drug and brain stimulation study
Abstract
Recommendation: posted 07 March 2025, validated 07 March 2025
Sherman, M. (2025) Does dopamine availability influence the effect of brain stimulation on mind-wandering?. Peer Community in Registered Reports, 100933. 10.24072/pci.rr.100933
This is a stage 2 based on:
Tara Rasmussen, Paul E. Dux and Hannah Filmer
https://osf.io/2trvp?view_only=09d64657b40e4b86b667582390bfdcb4
Recommendation
Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question was generated until after IPA.
List of eligible PCI RR-friendly journals:
The recommender in charge of the evaluation of the article and the reviewers declared that they have no conflict of interest (as defined in the code of conduct of PCI) with the authors or with the content of the article.
Evaluation round #1
DOI or URL of the report: https://www.biorxiv.org/content/10.1101/2024.11.02.620526v1
Version of the report: 1
Author's Reply, 19 Feb 2025
Decision by Maxine Sherman, posted 13 Jan 2025, validated 13 Jan 2025
Dear Tara Rasmussen,
Happy new year and my apologies for being so late in getting back to you. Thank you for submitting your Stage 2 manuscript, which stays true to your Stage 1 protocol and presents an interesting and rigourous study. I have received reviews on your Stage 2 submission from two of the original reviewers and as you'll see they're very enthusiastic, as am I. The two reviewers only have very minor suggestions for the discussion, to add titles to Fig 6, and for mapping the results back to the hypotheses.
I look forward to receiving your revised manuscript
Best wishes
Maxine
Reviewed by anonymous reviewer 1, 11 Dec 2024
The study reported no significant effect of HD-tDCS on thought modulation but highlighted a potential link between dopamine availability and reduced mind wandering. While the findings were comprehensive, I have a question for the discussion. The authors emphasized task sensitivity for internal thoughts, yet HD-tDCS showed no effect on task performance. Could varying task difficulty levels increase the likelihood of observing HD-tDCS effects? Are there studies that explore this relationship? Are there methodological challenges in designing tasks with varying difficulty within subject for HD-tDCS?
Minor suggestions:
- Add titles to the graphs in Figure 6 to provide context at a glance
- Cross-reference the hypotheses in the results section to connect these findings back to the introduction and research plan.
Reviewed by Chris Chambers, 25 Nov 2024
This is an excellent Stage 2 submission that in my view meets the evaluation criteria in its current state. The authors stayed close to their approved protocol and the reporting is very clear throughout, with a sensible and insightful discussion.
Even though evaluation of study rigour is not part of the Stage 2 assessment (being already covered at Stage 1), in reading the manuscript again I am reminded just how careful and thorough it was in the consideration of blinding, sample size planning, and a range of other design characteristics. This is a model approach for the application of tDCS that I hope other researchers follow.
I have one very minor suggestion: in the study design table, it would great to add a column to the far right called "Observed outcome" which states for each cell, very simply, whether the hypothesis was supported or not supported (based strictly on whether the results for that test met the preregistered inference criteria). For a complex study with many hypotheses, the inclusion of this additional column will provide a useful overview for readers and will make the outcomes easier to summarise in future SRs/meta-analyses.
Otherwise, I feel this manuscript makes an important contribution and would be happy for it to receive a positive recommendation.
